Refer to 0.2.1 in installation instructions

docs/installation_instructions.md

@@ -42,9 +42,9 @@ guide][https://openappstack.net/contact.html).
 ## Install OpenAppStack command line tool
 
 On your **provisioning machine**, clone the OpenAppStack git repository and
-checkout the latest tagged version (currently `0.2.0`):
+checkout the latest tagged version (currently `0.2.1`):
 
-    $ git clone -b 0.2.0 https://open.greenhost.net/openappstack/openappstack.git
+    $ git clone -b 0.2.1 https://open.greenhost.net/openappstack/openappstack.git
     $ cd openappstack